diff --git a/components/style/properties/build.py b/components/style/properties/build.py
index f9da76153a4..326859ea6d8 100644
--- a/components/style/properties/build.py
+++ b/components/style/properties/build.py
@@ -81,7 +81,7 @@ def write(directory, filename, content):
 def write_html(properties):
     properties = dict(
         (p.name, {
-            "flag": p.experimental,
+            "flag": p.servo_pref,
             "shorthand": hasattr(p, "sub_properties")
         })
         for p in properties.longhands + properties.shorthands
diff --git a/components/style/properties/data.py b/components/style/properties/data.py
index 8f35cf4150a..3aa4ad38b76 100644
--- a/components/style/properties/data.py
+++ b/components/style/properties/data.py
@@ -146,12 +146,12 @@ def arg_to_bool(arg):
 
 class Longhand(object):
     def __init__(self, style_struct, name, spec=None, animation_value_type=None, derived_from=None, keyword=None,
-                 predefined_type=None, custom_cascade=False, experimental=False, internal=False,
+                 predefined_type=None, custom_cascade=False, servo_pref=None, gecko_pref=None, internal=False,
                  need_index=False, custom_cascade_function=None, gecko_ffi_name=None,
                  allowed_in_keyframe_block=True, cast_type='u8',
                  logical=False, alias=None, extra_prefixes=None, boxed=False,
                  flags=None, allowed_in_page_rule=False, allow_quirks=False, ignored_when_colors_disabled=False,
-                 gecko_pref_ident=None, vector=False, need_animatable=False):
+                 vector=False, need_animatable=False):
         self.name = name
         if not spec:
             raise TypeError("Spec should be specified for %s" % name)
@@ -161,7 +161,8 @@ class Longhand(object):
         self.ident = to_rust_ident(name)
         self.camel_case = to_camel_case(self.ident)
         self.style_struct = style_struct
-        self.experimental = ("layout.%s.enabled" % name) if experimental else None
+        self.servo_pref = servo_pref
+        self.gecko_pref = gecko_pref
         self.custom_cascade = custom_cascade
         self.custom_cascade_function = custom_cascade_function if custom_cascade else None
         self.internal = internal
@@ -177,7 +178,6 @@ class Longhand(object):
         self.allowed_in_page_rule = arg_to_bool(allowed_in_page_rule)
         self.allow_quirks = allow_quirks
         self.ignored_when_colors_disabled = ignored_when_colors_disabled
-        self.gecko_pref_ident = gecko_pref_ident or self.ident
         self.is_vector = vector
 
         # https://drafts.csswg.org/css-animations/#keyframes
@@ -205,11 +205,25 @@ class Longhand(object):
             self.transitionable = False
             self.animation_type = None
 
+    def experimental(self, product):
+        if product == "gecko":
+            return bool(self.gecko_pref)
+        return bool(self.servo_pref)
+
+    # FIXME(emilio): Shorthand and Longhand should really share a base class.
+    def explicitly_enabled_in_ua_sheets(self):
+        return self.internal
+
+    # TODO(emilio): Change the `internal` field to something like `enabled_in`.
+    def explicitly_enabled_in_chrome(self):
+        return False
+
 
 class Shorthand(object):
-    def __init__(self, name, sub_properties, spec=None, experimental=False, internal=False,
+    def __init__(self, name, sub_properties, spec=None, servo_pref=None, gecko_pref=None,
+                 internal=False,
                  allowed_in_keyframe_block=True, alias=None, extra_prefixes=None,
-                 allowed_in_page_rule=False, flags=None, gecko_pref_ident=None):
+                 allowed_in_page_rule=False, flags=None):
         self.name = name
         if not spec:
             raise TypeError("Spec should be specified for %s" % name)
@@ -217,14 +231,14 @@ class Shorthand(object):
         self.ident = to_rust_ident(name)
         self.camel_case = to_camel_case(self.ident)
         self.derived_from = None
-        self.experimental = ("layout.%s.enabled" % name) if experimental else None
+        self.servo_pref = servo_pref
+        self.gecko_pref = gecko_pref
         self.sub_properties = sub_properties
         self.internal = internal
         self.alias = alias.split() if alias else []
         self.extra_prefixes = extra_prefixes.split() if extra_prefixes else []
         self.allowed_in_page_rule = arg_to_bool(allowed_in_page_rule)
         self.flags = flags.split() if flags else []
-        self.gecko_pref_ident = gecko_pref_ident or self.ident
 
         # https://drafts.csswg.org/css-animations/#keyframes
         # > The <declaration-list> inside of <keyframe-block> accepts any CSS property
@@ -252,18 +266,40 @@ class Shorthand(object):
     animatable = property(get_animatable)
     transitionable = property(get_transitionable)
 
+    def experimental(self, product):
+        if product == "gecko":
+            return bool(self.gecko_pref)
+        return bool(self.servo_pref)
+
+    def explicitly_enabled_in_ua_sheets(self):
+        return self.internal
+
+    def explicitly_enabled_in_chrome(self):
+        return False
+
 
 class Alias(object):
     def __init__(self, name, original):
         self.name = name
         self.ident = to_rust_ident(name)
         self.camel_case = to_camel_case(self.ident)
-        self.gecko_pref_ident = to_rust_ident(name)
         self.internal = original.internal
-        self.experimental = original.experimental
+        self.servo_pref = original.servo_pref
+        self.gecko_pref = original.gecko_pref
         self.allowed_in_page_rule = original.allowed_in_page_rule
         self.allowed_in_keyframe_block = original.allowed_in_keyframe_block
 
+    def experimental(self, product):
+        if product == "gecko":
+            return bool(self.gecko_pref)
+        return bool(self.servo_pref)
+
+    def explicitly_enabled_in_ua_sheets(self):
+        return self.internal
+
+    def explicitly_enabled_in_chrome(self):
+        return False
+
 
 class Method(object):
     def __init__(self, name, return_type=None, arg_types=None, is_mut=False):
diff --git a/components/style/properties/helpers.mako.rs b/components/style/properties/helpers.mako.rs
index 27d0cb907db..8dc422915d9 100644
--- a/components/style/properties/helpers.mako.rs
+++ b/components/style/properties/helpers.mako.rs
@@ -680,10 +680,9 @@
     % endif
 </%def>
 
-<%def name="shorthand(name, sub_properties, experimental=False, derive_serialize=False, **kwargs)">
+<%def name="shorthand(name, sub_properties, derive_serialize=False, **kwargs)">
 <%
-    shorthand = data.declare_shorthand(name, sub_properties.split(), experimental=experimental,
-                                       **kwargs)
+    shorthand = data.declare_shorthand(name, sub_properties.split(), **kwargs)
 %>
     % if shorthand:
     /// ${shorthand.spec}
diff --git a/components/style/properties/longhand/background.mako.rs b/components/style/properties/longhand/background.mako.rs
index 7518977522c..d6b9e6e69ba 100644
--- a/components/style/properties/longhand/background.mako.rs
+++ b/components/style/properties/longhand/background.mako.rs
@@ -92,6 +92,7 @@ ${helpers.single_keyword("background-blend-mode",
                             color-burn hard-light soft-light difference exclusion hue
                             saturation color luminosity""",
                          gecko_constant_prefix="NS_STYLE_BLEND",
+                         gecko_pref="layout.css.background-blend-mode.enabled",
                          vector=True, products="gecko", animation_value_type="discrete",
                          spec="https://drafts.fxtf.org/compositing/#background-blend-mode",
                          flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER")}
diff --git a/components/style/properties/longhand/border.mako.rs b/components/style/properties/longhand/border.mako.rs
index 070a68b85f0..89b707f90c0 100644
--- a/components/style/properties/longhand/border.mako.rs
+++ b/components/style/properties/longhand/border.mako.rs
@@ -191,6 +191,7 @@ ${helpers.gecko_keyword_conversion(Keyword('border-style',
 
 ${helpers.single_keyword("box-decoration-break", "slice clone",
                          gecko_enum_prefix="StyleBoxDecorationBreak",
+                         gecko_pref="layout.css.box-decoration-break.enabled",
                          spec="https://drafts.csswg.org/css-break/#propdef-box-decoration-break",
                          products="gecko", animation_value_type="discrete")}
 
diff --git a/components/style/properties/longhand/box.mako.rs b/components/style/properties/longhand/box.mako.rs
index f5f9d0753cd..ba014f1171f 100644
--- a/components/style/properties/longhand/box.mako.rs
+++ b/components/style/properties/longhand/box.mako.rs
@@ -239,7 +239,6 @@ ${helpers.single_keyword("position", "static absolute relative fixed sticky",
                                   gecko_enum_prefix="StyleFloat"
                                   gecko_inexhaustive="True"
                                   gecko_ffi_name="mFloat"
-                                  gecko_pref_ident="float_"
                                   flags="APPLIES_TO_FIRST_LETTER"
                                   spec="https://drafts.csswg.org/css-box/#propdef-float">
     impl ToComputedValue for SpecifiedValue {
@@ -375,6 +374,7 @@ ${helpers.single_keyword("-servo-overflow-clip-box", "padding-box content-box",
 
 ${helpers.single_keyword("overflow-clip-box", "padding-box content-box",
     products="gecko", animation_value_type="discrete", internal=True,
+    gecko_pref="layout.css.overflow-clip-box.enabled",
     flags="APPLIES_TO_PLACEHOLDER",
     spec="Internal, not web-exposed, \
           may be standardized in the future (https://developer.mozilla.org/en-US/docs/Web/CSS/overflow-clip-box)")}
@@ -543,6 +543,7 @@ ${helpers.predefined_type("animation-delay",
         "ScrollSnapPoint",
         "computed::ScrollSnapPoint::none()",
         animation_value_type="discrete",
+        gecko_pref="layout.css.scroll-snap.enabled",
         products="gecko",
         spec="Nonstandard (https://www.w3.org/TR/2015/WD-css-snappoints-1-20150326/#scroll-snap-points)",
     )}
@@ -552,6 +553,7 @@ ${helpers.predefined_type("scroll-snap-destination",
                           "Position",
                           "computed::Position::zero()",
                           products="gecko",
+                          gecko_pref="layout.css.scroll-snap.enabled",
                           boxed="True",
                           spec="Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/scroll-snap-destination)",
                           animation_value_type="discrete")}
@@ -562,6 +564,7 @@ ${helpers.predefined_type(
     "computed::Position::zero()",
     vector=True,
     products="gecko",
+    gecko_pref="layout.css.scroll-snap.enabled",
     spec="Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/scroll-snap-destination)",
     animation_value_type="discrete",
     allow_empty="NotInitial"
@@ -579,6 +582,7 @@ ${helpers.predefined_type("transform", "Transform",
 // https://www.w3.org/TR/cssom-view-1/
 ${helpers.single_keyword("scroll-behavior",
                          "auto smooth",
+                         gecko_pref="layout.css.scroll-behavior.property-enabled",
                          products="gecko",
                          spec="https://drafts.csswg.org/cssom-view/#propdef-scroll-behavior",
                          animation_value_type="discrete")}
@@ -590,6 +594,7 @@ ${helpers.single_keyword("scroll-behavior",
         "computed::ScrollSnapType::None",
         products="gecko",
         needs_context=False,
+        gecko_pref="layout.css.scroll-snap.enabled",
         spec="Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/scroll-snap-type-x)",
         animation_value_type="discrete"
     )}
@@ -600,6 +605,7 @@ ${helpers.single_keyword("scroll-behavior",
 ${helpers.single_keyword("isolation",
                          "auto isolate",
                          products="gecko",
+                         gecko_pref="layout.css.isolation.enabled",
                          spec="https://drafts.fxtf.org/compositing/#isolation",
                          flags="CREATES_STACKING_CONTEXT",
                          animation_value_type="discrete")}
@@ -666,6 +672,7 @@ ${helpers.single_keyword("transform-box",
                          "border-box fill-box view-box",
                          gecko_enum_prefix="StyleGeometryBox",
                          products="gecko",
+                         gecko_pref="svg.transform-box.enabled",
                          spec="https://drafts.csswg.org/css-transforms/#transform-box",
                          gecko_inexhaustive="True",
                          animation_value_type="discrete")}
@@ -693,6 +700,7 @@ ${helpers.predefined_type("transform-origin",
 // also update the glue once they are implemented in gecko.
 <%helpers:longhand name="contain" animation_value_type="discrete" products="gecko"
                    flags="FIXPOS_CB"
+                   gecko_pref="layout.css.contain.enabled",
                    spec="https://drafts.csswg.org/css-contain/#contain-property">
     use std::fmt;
     use style_traits::ToCss;
@@ -894,6 +902,7 @@ ${helpers.predefined_type(
     "generics::basic_shape::ShapeSource::None",
     products="gecko",
     boxed=True,
+    gecko_pref="layout.css.shape-outside.enabled",
     animation_value_type="ComputedValue",
     flags="APPLIES_TO_FIRST_LETTER",
     spec="https://drafts.csswg.org/css-shapes/#shape-outside-property",
@@ -902,6 +911,7 @@ ${helpers.predefined_type(
 <%helpers:longhand name="touch-action"
                    products="gecko"
                    animation_value_type="discrete"
+                   gecko_pref="layout.css.touch_action.enabled"
                    spec="https://compat.spec.whatwg.org/#touch-action">
     use gecko_bindings::structs;
     use std::fmt;
diff --git a/components/style/properties/longhand/column.mako.rs b/components/style/properties/longhand/column.mako.rs
index 1d938a256d8..c45ce687a03 100644
--- a/components/style/properties/longhand/column.mako.rs
+++ b/components/style/properties/longhand/column.mako.rs
@@ -12,7 +12,7 @@ ${helpers.predefined_type("column-width",
                           initial_specified_value="Either::Second(Auto)",
                           extra_prefixes="moz",
                           animation_value_type="NonNegativeLengthOrAuto",
-                          experimental=True,
+                          servo_pref="layout.column-width.enabled",
                           spec="https://drafts.csswg.org/css-multicol/#propdef-column-width")}
 
 
@@ -20,7 +20,7 @@ ${helpers.predefined_type("column-count",
                           "PositiveIntegerOrAuto",
                           "Either::Second(Auto)",
                           initial_specified_value="Either::Second(Auto)",
-                          experimental="True",
+                          servo_pref="layout.column-count.enabled",
                           animation_value_type="PositiveIntegerOrAuto",
                           extra_prefixes="moz",
                           spec="https://drafts.csswg.org/css-multicol/#propdef-column-count")}
@@ -29,7 +29,7 @@ ${helpers.predefined_type("column-gap",
                           "length::NonNegativeLengthOrNormal",
                           "Either::Second(Normal)",
                           extra_prefixes="moz",
-                          experimental=True,
+                          servo_pref="layout.column-gap.enabled",
                           animation_value_type="NonNegativeLengthOrNormal",
                           spec="https://drafts.csswg.org/css-multicol/#propdef-column-gap")}
 
@@ -62,6 +62,7 @@ ${helpers.predefined_type(
 
 ${helpers.single_keyword("column-span", "none all",
                          products="gecko", animation_value_type="discrete",
+                         gecko_pref="layout.css.column-span.enabled",
                          spec="https://drafts.csswg.org/css-multicol/#propdef-column-span")}
 
 ${helpers.single_keyword("column-rule-style",
diff --git a/components/style/properties/longhand/effects.mako.rs b/components/style/properties/longhand/effects.mako.rs
index bec6cae249b..1e9cb575f3f 100644
--- a/components/style/properties/longhand/effects.mako.rs
+++ b/components/style/properties/longhand/effects.mako.rs
@@ -52,4 +52,5 @@ ${helpers.single_keyword("mix-blend-mode",
                             saturation color luminosity""", gecko_constant_prefix="NS_STYLE_BLEND",
                          animation_value_type="discrete",
                          flags="CREATES_STACKING_CONTEXT",
+                         gecko_pref="layout.css.mix-blend-mode.enabled",
                          spec="https://drafts.fxtf.org/compositing/#propdef-mix-blend-mode")}
diff --git a/components/style/properties/longhand/font.mako.rs b/components/style/properties/longhand/font.mako.rs
index 428d9d8c1c1..726843b2373 100644
--- a/components/style/properties/longhand/font.mako.rs
+++ b/components/style/properties/longhand/font.mako.rs
@@ -1065,6 +1065,7 @@ https://drafts.csswg.org/css-fonts-4/#low-level-font-variation-settings-control-
 ${helpers.predefined_type("font-variation-settings",
                           "FontVariantSettings",
                           products="gecko",
+                          gecko_pref="layout.css.font-variations.enabled",
                           initial_value="specified::FontVariantSettings::normal()",
                           animation_value_type="ComputedValue",
                           flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
@@ -1372,6 +1373,7 @@ ${helpers.single_keyword("-moz-osx-font-smoothing",
                          "auto grayscale",
                          gecko_constant_prefix="NS_FONT_SMOOTHING",
                          gecko_ffi_name="mFont.smoothing",
+                         gecko_pref="layout.css.osx-font-smoothing.enabled",
                          products="gecko",
                          spec="Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/font-smooth)",
                          flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
diff --git a/components/style/properties/longhand/inherited_box.mako.rs b/components/style/properties/longhand/inherited_box.mako.rs
index 56887723678..2002f868d89 100644
--- a/components/style/properties/longhand/inherited_box.mako.rs
+++ b/components/style/properties/longhand/inherited_box.mako.rs
@@ -22,7 +22,7 @@ ${helpers.single_keyword("writing-mode",
                          extra_gecko_aliases="lr=horizontal-tb lr-tb=horizontal-tb \
                                               rl=horizontal-tb rl-tb=horizontal-tb \
                                               tb=vertical-rl   tb-rl=vertical-rl",
-                         experimental=True,
+                         servo_pref="layout.writing-mode.enabled",
                          animation_value_type="discrete",
                          spec="https://drafts.csswg.org/css-writing-modes/#propdef-writing-mode")}
 
@@ -41,6 +41,7 @@ ${helpers.single_keyword("text-orientation",
 // https://drafts.csswg.org/css-color/
 ${helpers.single_keyword("color-adjust",
                          "economy exact", products="gecko",
+                         gecko_pref="layout.css.color-adjust.enabled",
                          animation_value_type="discrete",
                          spec="https://drafts.csswg.org/css-color/#propdef-color-adjust")}
 
@@ -60,6 +61,7 @@ ${helpers.single_keyword("image-rendering",
 <%helpers:longhand name="image-orientation"
                    products="gecko"
                    animation_value_type="discrete"
+                   gecko_pref="layout.css.image-orientation.enabled"
     spec="https://drafts.csswg.org/css-images/#propdef-image-orientation, \
       /// additional values in https://developer.mozilla.org/en-US/docs/Web/CSS/image-orientation">
     use std::fmt;
diff --git a/components/style/properties/longhand/inherited_svg.mako.rs b/components/style/properties/longhand/inherited_svg.mako.rs
index 5f1e41ba0da..c1ae5365bf2 100644
--- a/components/style/properties/longhand/inherited_svg.mako.rs
+++ b/components/style/properties/longhand/inherited_svg.mako.rs
@@ -132,6 +132,7 @@ ${helpers.predefined_type("marker-end", "UrlOrNone", "Either::Second(None_)",
 
 <%helpers:longhand name="paint-order"
                    animation_value_type="discrete"
+                   gecko_pref="svg.paint-order.enabled"
                    products="gecko"
                    spec="https://www.w3.org/TR/SVG2/painting.html#PaintOrder">
     use std::fmt;
diff --git a/components/style/properties/longhand/inherited_text.mako.rs b/components/style/properties/longhand/inherited_text.mako.rs
index 981132730a9..cc3ae4d52b1 100644
--- a/components/style/properties/longhand/inherited_text.mako.rs
+++ b/components/style/properties/longhand/inherited_text.mako.rs
@@ -66,6 +66,7 @@ ${helpers.single_keyword("word-break",
                                   extra_specified="${'distribute' if product == 'gecko' else ''}"
                                   gecko_enum_prefix="StyleTextJustify"
                                   animation_value_type="discrete"
+                                  gecko_pref="layout.css.text-justify.enabled"
                                   flags="APPLIES_TO_PLACEHOLDER",
                                   spec="https://drafts.csswg.org/css-text/#propdef-text-justify">
 
@@ -689,6 +690,7 @@ ${helpers.predefined_type(
     "Color",
     "computed_value::T::currentcolor()",
     products="gecko",
+    gecko_pref="layout.css.prefixes.webkit",
     animation_value_type="AnimatedColor",
     ignored_when_colors_disabled=True,
     flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
@@ -703,6 +705,7 @@ ${helpers.predefined_type(
     products="gecko",
     animation_value_type="AnimatedColor",
     ignored_when_colors_disabled=True,
+    gecko_pref="layout.css.prefixes.webkit",
     flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
     spec="https://compat.spec.whatwg.org/#the-webkit-text-stroke-color",
 )}
@@ -713,6 +716,7 @@ ${helpers.predefined_type("-webkit-text-stroke-width",
                           initial_specified_value="specified::BorderSideWidth::Length(specified::Length::zero())",
                           computed_type="::values::computed::NonNegativeLength",
                           products="gecko",
+                          gecko_pref="layout.css.prefixes.webkit",
                           flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
                           spec="https://compat.spec.whatwg.org/#the-webkit-text-stroke-width",
                           animation_value_type="discrete")}
@@ -732,6 +736,7 @@ ${helpers.single_keyword("ruby-position", "over under",
 
 ${helpers.single_keyword("text-combine-upright", "none all",
                          products="gecko", animation_value_type="discrete",
+                         gecko_pref="layout.css.text-combine-upright.enabled",
                          spec="https://drafts.csswg.org/css-writing-modes-3/#text-combine-upright")}
 
 // SVG 1.1: Section 11 - Painting: Filling, Stroking and Marker Symbols
diff --git a/components/style/properties/longhand/position.mako.rs b/components/style/properties/longhand/position.mako.rs
index e228ca9056d..179ef350c1a 100644
--- a/components/style/properties/longhand/position.mako.rs
+++ b/components/style/properties/longhand/position.mako.rs
@@ -257,6 +257,7 @@ ${helpers.predefined_type("object-position",
                               "computed::NonNegativeLengthOrPercentage::zero()",
                               spec="https://drafts.csswg.org/css-grid/#propdef-grid-%s-gap" % kind,
                               animation_value_type="NonNegativeLengthOrPercentage",
+                              gecko_pref="layout.css.grid.enabled",
                               products="gecko")}
 
     % for range in ["start", "end"]:
@@ -266,6 +267,7 @@ ${helpers.predefined_type("object-position",
                                   animation_value_type="discrete",
                                   spec="https://drafts.csswg.org/css-grid/#propdef-grid-%s-%s" % (kind, range),
                                   products="gecko",
+                                  gecko_pref="layout.css.grid.enabled",
                                   boxed=True)}
     % endfor
 
@@ -277,6 +279,7 @@ ${helpers.predefined_type("object-position",
                               animation_value_type="discrete",
                               spec="https://drafts.csswg.org/css-grid/#propdef-grid-auto-%ss" % kind,
                               products="gecko",
+                              gecko_pref="layout.css.grid.enabled",
                               boxed=True)}
 
     ${helpers.predefined_type("grid-template-%ss" % kind,
@@ -285,6 +288,7 @@ ${helpers.predefined_type("object-position",
                               products="gecko",
                               spec="https://drafts.csswg.org/css-grid/#propdef-grid-template-%ss" % kind,
                               boxed=True,
+                              gecko_pref="layout.css.grid.enabled",
                               animation_value_type="discrete")}
 
 % endfor
@@ -292,6 +296,7 @@ ${helpers.predefined_type("object-position",
 <%helpers:longhand name="grid-auto-flow"
         spec="https://drafts.csswg.org/css-grid/#propdef-grid-auto-flow"
         products="gecko"
+        gecko_pref="layout.css.grid.enabled"
         animation_value_type="discrete">
     use std::fmt;
     use style_traits::ToCss;
@@ -415,6 +420,7 @@ ${helpers.predefined_type("object-position",
         spec="https://drafts.csswg.org/css-grid/#propdef-grid-template-areas"
         products="gecko"
         animation_value_type="discrete"
+        gecko_pref="layout.css.grid.enabled"
         boxed="True">
     use hash::FnvHashMap;
     use std::fmt;
diff --git a/components/style/properties/longhand/text.mako.rs b/components/style/properties/longhand/text.mako.rs
index f4e485eb363..fed1ce65c80 100644
--- a/components/style/properties/longhand/text.mako.rs
+++ b/components/style/properties/longhand/text.mako.rs
@@ -62,4 +62,5 @@ ${helpers.predefined_type(
     animation_value_type="discrete",
     products="gecko",
     flags="APPLIES_TO_FIRST_LETTER",
+    gecko_pref="layout.css.initial-letter.enabled",
     spec="https://drafts.csswg.org/css-inline/#sizing-drop-initials")}
diff --git a/components/style/properties/properties.mako.rs b/components/style/properties/properties.mako.rs
index 8dcb484df71..a3471dc41d3 100644
--- a/components/style/properties/properties.mako.rs
+++ b/components/style/properties/properties.mako.rs
@@ -184,6 +184,7 @@ pub mod shorthands {
         data.declare_shorthand(
             "all",
             logical_longhands + other_longhands,
+            gecko_pref="layout.css.all-shorthand.enabled",
             spec="https://drafts.csswg.org/css-cascade-3/#all-shorthand"
         )
     %>
@@ -238,7 +239,7 @@ impl NonCustomPropertyIdSet {
 static ${name}: NonCustomPropertyIdSet = NonCustomPropertyIdSet {
     <%
         storage = [0] * ((len(data.longhands) + len(data.shorthands) + len(data.all_aliases()) - 1 + 32) / 32)
-        for i, property in enumerate(data.longhands + data.shorthands):
+        for i, property in enumerate(data.longhands + data.shorthands + data.all_aliases()):
             if is_member(property):
                 storage[i / 32] |= 1 << (i % 32)
     %>
@@ -1157,6 +1158,7 @@ impl PropertyId {
             Some(context) => context,
             None => {
                 default = PropertyParserContext {
+                    in_chrome_stylesheet: false,
                     stylesheet_origin: Origin::Author,
                     rule_type: CssRuleType::Style,
                 };
@@ -1286,84 +1288,76 @@ impl PropertyId {
             _ => {}
         }
 
-        // For properties that are experimental but not internal, the pref will
-        // control its availability in all sheets.   For properties that are
-        // both experimental and internal, the pref only controls its
-        // availability in non-UA sheets (and in UA sheets it is always available).
-        ${id_set("INTERNAL", lambda p: p.internal)}
-
-        % if product == "servo":
-            ${id_set("EXPERIMENTAL", lambda p: p.experimental)}
-        % endif
-        % if product == "gecko":
-            use gecko_bindings::structs::root::mozilla;
-            static EXPERIMENTAL: NonCustomPropertyIdSet = NonCustomPropertyIdSet {
-                <%
-                    grouped = []
-                    properties = data.longhands + data.shorthands + data.all_aliases()
-                    while properties:
-                        grouped.append(properties[:32])
-                        properties = properties[32:]
-                %>
-                storage: [
-                    % for group in grouped:
-                        (0
-                        % for i, property in enumerate(group):
-                            | ((mozilla::SERVO_PREF_ENABLED_${property.gecko_pref_ident} as u32) << ${i})
-                        % endfor
-                        ),
-                    % endfor
-                ]
-            };
-        % endif
+        // The semantics of these are kinda hard to reason about, what follows
+        // is a description of the different combinations that can happen with
+        // these three sets.
+        //
+        // Experimental properties are generally controlled by prefs, but an
+        // experimental property explicitly enabled in certain context (UA or
+        // chrome sheets) is always usable in the context regardless of the
+        // pref value.
+        //
+        // Non-experimental properties are either normal properties which are
+        // usable everywhere, or internal-only properties which are only usable
+        // in certain context they are explicitly enabled in.
+        ${id_set("ENABLED_IN_UA_SHEETS", lambda p: p.explicitly_enabled_in_ua_sheets())}
+        ${id_set("ENABLED_IN_CHROME", lambda p: p.explicitly_enabled_in_chrome())}
+        ${id_set("EXPERIMENTAL", lambda p: p.experimental(product))}
+        ${id_set("ALWAYS_ENABLED", lambda p: not p.experimental(product) and not p.explicitly_enabled_in_ua_sheets())}
 
         let passes_pref_check = || {
             % if product == "servo":
                 static PREF_NAME: [Option< &str>; ${len(data.longhands) + len(data.shorthands)}] = [
                     % for property in data.longhands + data.shorthands:
-                        % if property.experimental:
-                            Some("${property.experimental}"),
+                        % if property.servo_pref:
+                            Some("${property.servo_pref}"),
                         % else:
                             None,
                         % endif
                     % endfor
                 ];
-                match PREF_NAME[id.0] {
-                    None => true,
-                    Some(pref) => PREFS.get(pref).as_boolean().unwrap_or(false)
-                }
-            % endif
-            % if product == "gecko":
+                let pref = match PREF_NAME[id.0] {
+                    None => return true,
+                    Some(pref) => pref,
+                };
+
+                PREFS.get(pref).as_boolean().unwrap_or(false)
+            % else:
                 let id = match alias {
                     Some(alias_id) => alias_id.to_nscsspropertyid().unwrap(),
                     None => self.to_nscsspropertyid().unwrap(),
                 };
+
                 unsafe { structs::nsCSSProps_gPropertyEnabled[id as usize] }
             % endif
         };
 
-        if INTERNAL.contains(id) {
-            if context.stylesheet_origin != Origin::UserAgent {
-                if EXPERIMENTAL.contains(id) {
-                    if !passes_pref_check() {
-                        return Err(())
-                    }
-                } else {
-                    return Err(())
-                }
-            }
-        } else {
-            if EXPERIMENTAL.contains(id) && !passes_pref_check() {
-                return Err(());
-            }
+        if ALWAYS_ENABLED.contains(id) {
+            return Ok(())
         }
 
-        Ok(())
+        if EXPERIMENTAL.contains(id) && passes_pref_check() {
+            return Ok(())
+        }
+
+        if context.stylesheet_origin == Origin::UserAgent &&
+            ENABLED_IN_UA_SHEETS.contains(id)
+        {
+            return Ok(())
+        }
+
+        if context.in_chrome_stylesheet && ENABLED_IN_CHROME.contains(id) {
+            return Ok(())
+        }
+
+        Err(())
     }
 }
 
 /// Parsing Context for PropertyId.
 pub struct PropertyParserContext {
+    /// Whether the property is parsed in a chrome:// stylesheet.
+    pub in_chrome_stylesheet: bool,
     /// The Origin of the stylesheet, whether it's a user,
     /// author or user-agent stylesheet.
     pub stylesheet_origin: Origin,
@@ -1375,6 +1369,7 @@ impl PropertyParserContext {
     /// Creates a PropertyParserContext with given stylesheet origin and rule type.
     pub fn new(context: &ParserContext) -> Self {
         Self {
+            in_chrome_stylesheet: context.in_chrome_stylesheet(),
             stylesheet_origin: context.stylesheet_origin,
             rule_type: context.rule_type(),
         }
diff --git a/components/style/properties/shorthand/box.mako.rs b/components/style/properties/shorthand/box.mako.rs
index 4a058b5b7ab..26371090716 100644
--- a/components/style/properties/shorthand/box.mako.rs
+++ b/components/style/properties/shorthand/box.mako.rs
@@ -331,6 +331,7 @@ macro_rules! try_parse_one {
 </%helpers:shorthand>
 
 <%helpers:shorthand name="scroll-snap-type" products="gecko"
+                    gecko_pref="layout.css.scroll-snap.enabled"
                     sub_properties="scroll-snap-type-x scroll-snap-type-y"
                     spec="https://drafts.csswg.org/css-scroll-snap/#propdef-scroll-snap-type">
     use properties::longhands::scroll_snap_type_x;
@@ -360,6 +361,7 @@ macro_rules! try_parse_one {
 
 <%helpers:shorthand name="-moz-transform" products="gecko"
                     sub_properties="transform"
+                    gecko_pref="layout.css.prefixes.transforms"
                     flags="SHORTHAND_ALIAS_PROPERTY"
                     derive_serialize="True"
                     spec="Non-standard: https://developer.mozilla.org/en-US/docs/Web/CSS/transform">
diff --git a/components/style/properties/shorthand/column.mako.rs b/components/style/properties/shorthand/column.mako.rs
index cf1071def1e..a382850b672 100644
--- a/components/style/properties/shorthand/column.mako.rs
+++ b/components/style/properties/shorthand/column.mako.rs
@@ -6,7 +6,7 @@
 
 <%helpers:shorthand name="columns"
                     sub_properties="column-width column-count"
-                    experimental="True"
+                    servo_pref="layout.columns.enabled",
                     derive_serialize="True"
                     extra_prefixes="moz" spec="https://drafts.csswg.org/css-multicol/#propdef-columns">
     use properties::longhands::{column_count, column_width};
diff --git a/components/style/properties/shorthand/inherited_text.mako.rs b/components/style/properties/shorthand/inherited_text.mako.rs
index 664d5238d57..95850f5c043 100644
--- a/components/style/properties/shorthand/inherited_text.mako.rs
+++ b/components/style/properties/shorthand/inherited_text.mako.rs
@@ -46,6 +46,7 @@
 <%helpers:shorthand name="-webkit-text-stroke"
                     sub_properties="-webkit-text-stroke-width
                                     -webkit-text-stroke-color"
+                    gecko_pref="layout.css.prefixes.webkit"
                     products="gecko"
                     derive_serialize="True"
                     spec="https://compat.spec.whatwg.org/#the-webkit-text-stroke">
diff --git a/components/style/properties/shorthand/position.mako.rs b/components/style/properties/shorthand/position.mako.rs
index 188ae94dcda..a04283c0321 100644
--- a/components/style/properties/shorthand/position.mako.rs
+++ b/components/style/properties/shorthand/position.mako.rs
@@ -103,6 +103,7 @@
 </%helpers:shorthand>
 
 <%helpers:shorthand name="grid-gap" sub_properties="grid-row-gap grid-column-gap"
+                    gecko_pref="layout.css.grid.enabled"
                     spec="https://drafts.csswg.org/css-grid/#propdef-grid-gap"
                     products="gecko">
   use properties::longhands::{grid_row_gap, grid_column_gap};
@@ -134,6 +135,7 @@
 
 % for kind in ["row", "column"]:
 <%helpers:shorthand name="grid-${kind}" sub_properties="grid-${kind}-start grid-${kind}-end"
+                    gecko_pref="layout.css.grid.enabled"
                     spec="https://drafts.csswg.org/css-grid/#propdef-grid-${kind}"
                     products="gecko">
     use values::specified::GridLine;
@@ -173,6 +175,7 @@
 % endfor
 
 <%helpers:shorthand name="grid-area"
+                    gecko_pref="layout.css.grid.enabled"
                     sub_properties="grid-row-start grid-row-end grid-column-start grid-column-end"
                     spec="https://drafts.csswg.org/css-grid/#propdef-grid-area"
                     products="gecko">
@@ -238,6 +241,7 @@
 </%helpers:shorthand>
 
 <%helpers:shorthand name="grid-template"
+                    gecko_pref="layout.css.grid.enabled"
                     sub_properties="grid-template-rows grid-template-columns grid-template-areas"
                     spec="https://drafts.csswg.org/css-grid/#propdef-grid-template"
                     products="gecko">
@@ -459,6 +463,7 @@
 </%helpers:shorthand>
 
 <%helpers:shorthand name="grid"
+                    gecko_pref="layout.css.grid.enabled"
                     sub_properties="grid-template-rows grid-template-columns grid-template-areas
                                     grid-auto-rows grid-auto-columns grid-auto-flow"
                     spec="https://drafts.csswg.org/css-grid/#propdef-grid"